High levels of fatty substances in the blood increase the risk of developing heart disease. Investigators know a lot about one of these fatty substances, cholesterol. However, there is another fatty substance in the blood called triglyceride. Investigators do not understand much about what regulates the rate at which the liver produces triglyceride and liberates it into the bloodstream after eating a meal(s). It is known that taking fish oil lowers the amount of blood triglyceride however, it remains unclear how this happens. Investigators will study if changes in liver fat metabolism, after taking fatty acids found in fish oil (n-3 fatty acids)can explain the lowering of blood triglyceride. Investigators also want to know if taking fish oil alters the amount of fat that accumulates within the liver.